Furnace for calcining copper and like ores.



1.6. SQUlRE. FURNACE FOR CALCINING COPPER Mm LIKE oass.

APPLICATION FILED FEB. 14. 1917- Patented Apr. 9, 1918.

3 SHEETS-SHEET l. F/Q 1' J. G. SQUiRE. FURNACE FOB CYALCINING COPPER AND um: ORES.

APPLICATION FILED FEB. 14. 19]]- Patented Apr. 9, 1918.

3 SHEETS-SHEET 2 fl w 5 a W K 8 n I. G. s uImiJ FURNACE FOR CALCINING COPPER AND LIKE ORES.

APPLICATION FILED FEB. I4. 1917.

1,262,126, Patented Apr. 9,1918.

3 SHEETS-SHEET 3.

HQ 13. 60 v if] cans, such as inde- Way valves, are provlcied Whereependently of the $5 cs so as to 1nd1 adial arms lob forms a mo onprises 1' y of hot and cold air to each e can be controlled 1nd ahe other rabbl perature 1n each cai- 1 hollow shaft tarv rabbles.

to dually control the tern rabble 00 33v a the nil y toe sup Each ro arried for pencie Tabb sup

cinmg' chamber.

hlby

ted

mvention is 1011 of furnace es free from to big duce ouprlc ch 1s very soluble n 131 extras kc or lcining y and economioa 1e presen .mroved construct e amoum Oi alr supduring ca and pro W111i in ining copper and 1 e above dlsadvantages, that 15 Wherem y 1s an adequa" said charge QGuCL ne object of U rovlde an plied to the charge lize chlorld p for calc both t not on oxic 3 so Water and easil conduit and incloses conduits for hot .or

cold air, said radial arms carrying a series of teeth provided with passages commumeating with one'of said central air conduits whereby hot or cold air supplied to said conduit is delivered to the charge in the calcining chambers. The teeth of the radial armsare set with their blades at varying angles 'to their arms. Means are also provided for adjusting the central hollow shaft' carrying the rotary rabbles whereby the teeth thereof can be adjusted relatively to the floors of thecalcining chambers.

The accompanying drawingsillustrate, by

way of examplefone construction of cal-,

cining 'furnace embodying -my invention. In the drawings- Figure 1 is a'central vertical section of the furnace;

Figs. 2 3 and 4 are plan sections, to a smaller scale, on the lines A-A, 13-13 and C -C3 respectively in Fig. 1;

Figs. 5 and 6 are a part sectional plan and a part vertical section to a larger scale of one of the air supplying rabbles hereinafter described;

Fig. 7' is an elevation of the hub of one of said rabbles;

Fig. 8 is a section-on' the line D-D n Fig. 6;

Fig. 9 is a plan section of one of the teeth of said rabbles;

Fig. 10 is a diagrammatic plan of-ono of the rabbles;

Figs. 11 and 12 area lan section and a central vertical section il ustrating the four two-way valves hereinafteridescribed; and Fig.1?) is a plan of the base support and means for rotatingthe central shaft.-

, Referring to the drawings, the calcining furnace therein illustrated comprises three superposed circular calcining chambers '1, 2, 3 (Fig. 1). These chambers are heated by the flame and hot gases from fires 4, provided in the walls of the furnace adjacent to the upper chamber 1 and 'suppliedwith hot air. The hot gases and-products of combustion from the fires 4 are conducted through concentric heating flues 5 beneath the floor of the upper calcining chamber 1.

and pass from the periphery thereof toward the center (asindicated by arrows in Fig. 2) and are then led by vertical and horizontal fiues 6 to concentricheating flues 7 beneath the floor ofthe middle chamber 2 where they again pass from the periphery toward the center (as indicated by arrows in Fig. and are then led by vertical and horizontal flues 8 to concentric heating fiues 9 beneath the floor of the lower'chamber 3 where they pass from the center toward the periphery (as indicated by arrows in Fig. 4) and are then led away by vertical and horizontal flues 10' whichcommunicate with the main naeanae chimney flue through suitable conduits, as

'- underground passages indicated at 38 and 10 between Figs. 1 and 3. It will be seen that in the floor of eachcalcining chamber concentric heat zones are produced which vary in intensity, said zones gradually increasing in temperature from the center to the periphery of the floor of the upper chamber 1, decreasing in temperature from the periphery to the center of-the floor of the middle chamber 2, and decreasing in temperature from the center to the perip h.

cry of the floor of the lower chamber 3.

It willalso be seen that the products of combustion from the fires 1 do not enter any of the calcining chambers 1 2, 3 so that the charge'therein is not contaminated by said products 1 Opening out of the upper chamber 1 is an outlet 11 (Fig. 1) which conducts the gaseous or volatile products, sulfur dioxid,

eupric chlorid and hydrogen chlorid, from the calcining chambers to the usual condensers Y In each of the calcining chambers 1, 2, 3 I provide a rotary air-supplying rabble having four hollow radial arms 12 attached to a central hollow'verticalshaft l3.which is madein sections and passes through all the calcining chambers. The shaft 13 is supported by a bearing 14 at the top and a foostep bearing 15 at the bottom. The

radial arms .12 each carry a series of teeth '16 suitably spaced along the length of the arm. The teeth l6 have horizontal tubular heads 17 (Figs. 6 and 8) from which depend pipes 18 which form the stems of the teeth. The tubular heads 17-and pipes 18 form T-tubes the horizontal members of which communicate one with the other, the

horizontal members nearest the hubs 19 of the rabbles communicating with ports 20 (Fig. 6) leading from passages 21 into which open air supply pipes 22 in the interior'of the hollow shaft 13. A separate pipe 22 is provided for each rabble. The heads 17 of the teeth 16 are supported from the radial arms 12 by lateral projections 23 (Figs. 6 and 8) engaging corresponding grooves in the under portions 24c (Fig. 8) of the arms, axial movement of said heads being prevented by set screws 25 (Figs. 5 and 6) bearing on the outermost heads.

'The supply of air to the pipes 22 in the hollow central shaft 13 is controlled by three independent two-way valves 26 (Figs. 1, 11 and 12) each adapted to put one of said pipes into communication either with a central hot air supply pipe 27 or with cold air supply passages 28 fed by a blower 29 through a water seal 30. The cold air passes from the blower 29 into the annular chamber 29 and up through the vertical tubes 29 into the'upper portion of the seal memes 30 and through openings 29 therein into the passages 28. This is all shown clearly in Fig. 1. A fourth two-way valve is provided for permitting a supply of cold air to pass from the passages 28 into the hollow central shaft 13 for cooling said shaft. The four two-way valves are arranged 90 apart around the shaft 13. By manipulating the two-way valves 26 hot or cold air can be supplied to the teeth 16 of all or any one of the rabbles, as may be required. The hot air supply pipe 27 communicates at the top through apertures 31 with the interior of the dome-shaped doublesided cap 32 ofa hot air seal the base 33 of whichcomprises a double-sided vessel of U-section containing a refractory powder which may be iron ore, into which the cap 32 dips, said cap being fixed to and revolving with the shaft 13 while .the base 33 is stationary. Pipes 34: pass through the refractory powder in the hot air seal 32, 33 and lead hot air from a channel 35 opening out of a' hot air supply flue 36, and a valve 37 controls the admission of hot air to the channel 35. The air supplied to the flue 36 is admitted at atmospheric temperature to an air flue in the interior of the main chimney flue and passes up a flue 38 (Fig. 4:) to a circumferential air flue 39.beneath the floor of the lower calcining chamber 3 and thence up a flue 4.0 to a second circumferential flue 41 beneath the floor of the middle calcining chamber 2 and up flues 42 at each side to circumferential flues 43 in the wall of the furnace around the upper calcining chamber 1 which lead the heated air to the fires 4. 44 (Fig. 2) are gas supply flues for the cumferential hot air flue. 41 to the hot air ployed to aerate the charge in the calcining chambers and for the fires is heated by the.

waste heat of the furnace. The air to be heated may be" ropelled by a bloWer'or; c

traveled from thecenter toward the periph-' ery.of the floorjoftherupper chamber 1 by drawn-through t 9 y O flues by natura'l'chim draft I The cold air supplied to the; central Shaft 13 to cool'san'le becomes heatedas it passes therethrough an'd is allowed to-ent'er the-upper' calcining chamber 1 through apertures 46' (Fig. 1). -Itmay also be allewe'd to enter" all or any of the hollow arms 12 through ports 46 to cool said arms, the air in the shaft 13, though warm, being at lower" temperature thanthe'arms 12.

The aperture 47 inathe top of the furnace for1thecentral'shaft13 is closed by an ore sea 48.

The teeth 16 of each at 12 of the rab-' bles are set withtheir blades at diflerent angles to those of the adjacent arms. As

indicated in Fig. 10, the blades of the set oft'eeth same-a by: the am marked 1a are setat such an angle to the axis of said arm as to propel the charge from the center outward toward the circumference of the floor of the calcining chamber when the rabble is rotated in the direction indicated by the arrow ;-the blades of the set of teeth carried by the arm marked 12 are set at a reverse angle of the same degree as the blades 12 so as to return the charge towardthe center of the floor of the chamber. The blades of the set ofteeth carried by the arm marked 12.are'set at such an angle as to drive the charge toward the circumference of the floor of the chamber; while the blades of the set of teeth carried by the arm marked 12' are set parallel with the axis of said arm so as to merely distribute the charge over the floor ofthe chamber without exerting any propelling or retracting eflect thereon. It

will thus be seen that the blades of the .arms- The blades of the rabble teeth are arranged as above described in the upper calcining chamber 1 and gradually travel. the charge from the center of thatchamb'ertoward its periphery. 'In the middle chamber 2 the blades 12, 12 and 12 are oppositely arranged to those in chamber 1 so as to grad ually travel the charge from the periphery toward the center thereof. In the lower chamber the blades are arranged in the same manner as inchamber 1 and gradually travel the charge from the center toward the periphery thereof. The charge of ore'to be calcined is delivered in any suitable manner, for example by a screw conveyer 49 (Fig. 1), to a chute 50 which deposits it. near the center of the upper calciningchamber 1. The charge is the teeth of thera'bble' therein, beingthoroughly stirred thereby'to promote and fa cilitate the chemical. decomposition and to continuously. expose .freesurf-aces t0 the oxi? dining influence of the air issuing from the pipes 18 of the rabble teeth, and passes down chutes 51 (Fig.2) to the periphery of the floor of the middle'calcining chamthe floor of the lower chamber 3 by central chutes 52 and undergoes further agitating and aeratin in said chamber and finally perature therein.

passes from the periphery of the lower chamber by chutes 53 (Fig. 4) to the exterior of the furnace.

It will be seen that the movement of the charge is from the zone of lowest temperature in the fioor of the upper calcining chamber 1 to the zone of-highest temperature therein, from the zone of highest temperature in the floor of the middle calcining 'chamber 2 to the zone of lowest temperabevel Wheel 5. 'The bevel wheel 57 is driven by a bevel 58 on a shaft 59'whichis rotated by'power transmitted from a shaft 60 driven from any suitable source of rotary power.

Suitable means may be provided for driving the central vertical shaft 13 at different speeds if required, and provision is made, by means of a vertical screw 61 under the footstep bearing 15, for the vertical adjustment of the shaft 13 in order to adjust the teeth 16 of the rabbles to the correct distance from the floors of the calcining -chambers 1, 2, 3. The vertical screw 61 has fixed on it a worm wheel 62 which is engaged by a Worm on a shaft 63 provided with a hand-Wheel 64. t

As will be readily understood, the details of my improved calcining furnace may be considerably modified both in construction and arrangement without departing from the spirit of my' invention. For example, the two-way valves 26 controlling the supply of hot and cold air to the rabbles and to the shaft 13, and the hot air seal 32, 33

may be arranged at the top of the furnace, and the hot air fiues leading to the channel 35 correspondingly modified.

It will now be seen that, by my invention, I provide a calcining furnace wherein an adequate amount of air is supplied to the charge durin calcining and intimately mixed therewith, andthat the heat is so applied to the floors of the calcining cham- 13) on the shaft 56 of a This prevents the sodium sulfate solidifying and the consequent accumulation of a mass of solid sodium sulfate and ore upon the floors, which accumulation occurs where the calcining. chambers are heated from above, as is the usual practice, and where the floors are consequently cooler than the charge. In the furnace of the present invention the sodium sulfate solidifies within the charge and is discharged therewith. My improved construction insures the supply of the combining proportion of oxygen to the charge during the decomposition and thus provides a furnace which is essentially oxidizing, producing peroxids and cupric chlorid allowing 0 expeditious and economical lixiviation. The silver chlorid is subsequently dissolved in the cupric chlorid and can be recovered. Thehot air supplied to the chargeis heated by the Waste heat of the furnace, and the temperature of the charge can be regulated and controlled by supplying hot or cold air to the calcining chambers as required.

What I claim and desire to secure by Letters Patent is 1. A calcining furnace comprising a plurality of superposed calcining chambers, heating Hues beneath the floors of said chambers, said fiues being substantially horizontally arranged,'with certain ofthe fiues, at different distances from a predetermined point on a chamber floor, connected in series so as to produce heat zones of varying intensity in the floor of that chamber, means for introducing a charge to be calcined into said chambers, rotary rabbles in said chambers adapted to distribute, agitate, supply air to and travel the charge over the heat zones-in the floors of said chambers, means for supplyingair to said rabbles, and means fordischarging the calcined charge from said chambers.

2. A calcining furnace comprising a plurality of superposed calcining chambers,

- heating-flues-beneath the floors of said chambers 1, 2, 3 and the'charge so traveled over the'varying heating zones produced in said floors that the temperature of thecharge is gradually increaseduntil the desired tem-' pera'ture is attained and then gradually decreased. The temperature of the floors of the calcining chambers is higher than the temperature of the-charge on floors.

bers, said fiues being disposed so as individually to underlie various adjacent portions of a chamber and beingconnected 1n. series so 'as to produce heat zones of varying intensity in the floor of that chamber, means for introducing a charge to be calcined into said chambers, rotary rabbles 'in said chambers adapted to .distribute, agitate, supply air to the charge and travel the charge over-the heat zones in the floors of saidchambers, means for supplying air to said rabbles, and means for discharging the calcined charge from saidchambers- 3. A calcining furnace comprising a plurality of superposed calcining chambers, heating flues beneath the floors of said chambers, the flues beneath each chamber being horizontally. arranged and connected in se- 4:. A calcining furnace comprising a plurality of superposed calcimng chambers, heating flues beneath the floors of said chambers said flues being arranged so as to produce heat zones of varying intensity in said floors, means for introducing the charge to be calcined into said chambers, rotary rabbles in said chambers adapted to distribute, agitate, supply air to and travel the charge over the heat zones in the floors of said chambers, means for supplying air to said rabbles, means for discharging the calcined charge from said chambers, means for heating the air supplied -to said rabbles, and means for independently controlling said supply of heated air to any one of said rab- 5. A calcining furnace comprising a plurality of superposed calciningchambers, heating flues beneath the floors of said'cham- 'bers said flues being arranged so as to prochambers,

ber carried by said central shaft each rabble duce heat zones of varying intensity in said floors, means for introducing the charge to be calcined into said chambers, rotary rabbles in said chambers adapted to distribute,

agitate, supply air to and travel the charge over the heat zones in the floors of said chambers, means for supplying air to said rabbles, means for discharging the calcined charge from said chambers, air-heating flues adjacent to the calcining chambers by which the air supply for said rabbles is heated, and

means for independently controlling said supply of heatedair to any one of said rahbles.

6. A calcining furnace comprising a plu= rality of superposed calcining chambers, heatmg flues beneath the floors of said chambers said flues beingarranged so as to pro duce heat zones of varying intensity in said floors, means for introducing the charge to be calcined into said chambers, a hollow central shaft passing through all the calcining a rabble in each calcining chamcomprising radial arms carrying teeth ,dis

posed so as to distribute, agitate and travel the chargevover the heat zones in the floor .of the chamber, radial arms, independent air conduits inair pipes carried by said said central shaft each communicating with ihg said heated air to calcining chambers,

the air pipes of one rabble, means for heating a1r comprislng air-heating flues ad]acent to the calcining chambers, means for supplying said heated air to each of said air conduits, means for supplyingcold air to each'of said air conduits and to the central shaft, means for independently controlling said duits and central shaft, said central shaft, and means for ing the calcined charge from said chambers.

7. A calcining furnace comprising a plurality of superposed calcining chambers, heating flues beneath the floors of said chambers said flues being arranged so as to produce heat zones of varying intensity in supplies of hot andcold air to said conmeans for rotating 7 said floors, means for introducing the charge to be calcined into said chambers, a hollow central shaft passing through all of the calcining chambers, a rabble in each calcining chamber carried by said central shaft each rabble comprising radial arms carrying teeth disposed so as to distribute, agitate and travel the charge over the heat zones in the floor of the chamber, air pipes carried by said radial arms, independent air conduits in said central shaft each communicating with the air pipes of one rabble, means for heating air comprising air-heating flues adj acent to the calcining chambers, means for supplyeach of said air conduits, means for supplying cold air to each of said air conduits and to the central shaft, means .for independently controlling said supplies of hot and central shaft, means for rotating said central shaft, means for discharging the calcined charge "from said chambers, and means for vertically adj usting said central shaft.

8. A calcining furnace comprising a plu rality' of superposed calcining chambers, heating flues beneath the floors of said chambers said flues being arranged so as to produce heat zones of varying intensity in said floors, means for introducing the charge to be calcined into said chambers, a hollow central shaft passing through all the calcining chambers, a rabble in each calcining chamber carried by said central shaft each rabble comprising four radial arms spaced 90 apart carrying teeth, the teeth of two of said arms being oppositely inclined, the teeth of the third arm bein parallel thereto, and the teeth of the" fOUIl arm being inclined so dischargand cold air to said conduits thatsaid teeth distribute,-agitate and travel the charge over the heat zones in the floor of the chamber, air pipes carried by said radial arms, independent air conduits in said cen-.

'tral shaft each communicating with the air pipes of one rabble, means for heating air comprising air-heating flues adjacent to the said heated alr to each 'of said air conduits, means forsnpplying cold air to each of said means for supplyi g air conduits and to the central shaft, means for independently controlling said supplies of hot and cold a1r to said conduits and central shaft, means for rotating said central shaft, and means for discharging thecalcined charge from said chambers.

9. A calcining furnace comprising three superposed calcining chambers, concentric floor of the lower chamber adaptedto lead said hot gases'from the center toward the periphery thereof, means for delivering the charge to be calcined onto the floor of the upper chamber near the center thereof, a-

rotary rabble therein adapted to distribute, agitate, supply air toand travel the charge means -fioor of the intermediate chamber near the periphery thereof, a rotary rabble therein adapted to distribute, agitate, supply air to and travel the charge toward the center of said intermediate chamber, means for delivering said charge onto the floor of the lower chamber near the center thereof, a rotary rabble therein adapted to distribute, agitate, supply air to and travel the charge toward the periphery of said lower chamber, means for discharging said charge from said lower 4 chamber, and means for supplying air to said rabbles.

In testimony whereof -I have signed my name to this specification in the presence of two subscribing Witnesses.

JOHN G. SQUIRE. Witnesses: HERBERT HOWARD, GEORGE HAROLD APrLE'noN. 

